Method and apparatus for forming random slubs in yarn

ABSTRACT

Method and apparatus for forming in a yarn random slubs of random length and random diameter at random spaced intervals along the yarn. A slubbing yarn strand at a predetermined percent of overfeed and a core yarn strand under predetermined tension are introduced through separate inlets into one end of a slubbing chamber. The inlet for the slubbing yarn strand is a jet, which introduces into the chamber along with the slubbing yarn strand a first stream flow of compressible liquid. The outlet from the chamber for both yarn strands is a second jet, which introduces into the chamber a second stream flow of compressible liquid, the two stream flows being directed generally toward each other. The stream flows from the jets are adjusted to support the slubbing yarn strand generally free from contact with the chamber wall, and to move the slubbing yarn strand freely about in the chamber relative to the core yarn strand, forming slubs and entwining and entangling with the core yarn strand. The two strands exit together from the chamber through the second jet countercurrent to the second stream flow consolidating the slubbing yarn strand with the core yarn strand, and thus a more unitized yarn bundle is formed.

1451 May28, 1974 METHOD AND APPARATUS FOR FORMING RANDOM SLUBS IN YARN Kenneth W. Holland, Kingsport, Tenn.

[75 Inventor:

[73] Assignee: Eastman Kodak Company,

Rochester, NY.

221 Filed: Dec.22, 1972 21 Appl. N6; 317,561

[56] References Cited UNITED STATES PATENTS 3,174,271 3/1965 Edwards et al 57/157 F X 3,296,785 l/1967 Hardy 28/7211 X 3,474,613 10/1969 .loarder et al. 57/157 F 3,727,275 4/1973 Ohayon..; 28/1.4 3,729,831 s/1973 Kos akaetal 2s 1 .4 x

Primary Examiner.lohn W. Huckert Assistant ExaminerCharles Gorenstein Attorney, Agent, or Firm-Malcolm G. Dunn [57] ABSTRACT Method and apparatus for forming in a yarn random slubs of random length and random diameter at random spaced intervals along the yarn. A slubbing yarn strand at a predetermined percent of overfeed and a core yarn strand under predetermined tension are introduced through separate inlets into one end of a slubbing chamber. The inlet for the slubbing yarn strand is a jet, which introduces into the chamber along with the slubbing yarn strand a first stream flow of compressible liquid. The outlet from the chamber for both yarn strands is a second jet, which introduces into the chamber a second stream flow of compressible liquid, the two stream flows being directed generally toward each other. The stream flows from the jets are adjusted to support the slubbing yarn strand generally free from contact with the chamberwall, and to move the slubbing yarn strand freely about in the chamber relative to the core yarnstrand, forming slubs and entwining and entangling with the core yarn strand. The two strands exit together from the chamber through the second jet countercurrent to the sec ond stream flow consolidating the slubbing yarn strand with the core yarn strand, and thus a more unitized yarn bundle is formed.

18 Claims, 5 Drawing Figures i'ATENTEDlAY2 1914 3,812,665

F77um u L um I METHOD AND APPARATUS FOR FORMING 1 RANDOM SLUBS IN YARN BACKGROUND OF THE INVENTION The present invention is directed to a method and an apparatus for practicing the method for forming yam slubs of random length and random diameter at random spaced intervals.

It is old in the art to form slubs in yarn to produce certain desired novelty effects in fabrics made from the slubbed yarn. Slub yarns of the type to which this invention relates are conventionally produced by feeding a core yarn strand and simultaneously overfeeding a wrapping strand or slubbing yarn strand into some suitable mechanism by which the overfed wrapped strand or slubbing yarn strand is entangled or adhered to the core yarn strand. The overfed strand thus forms with the core yarn strand along the length of the yarn slubs having thickened portions or cross-sections of predetermined length and predetermined diameters, with the slubs either tapering at the ends or being abruptly terminated. depending upon the desired novelty effects to be achieved in the fabric to be made. Such slubs impart texture and surface interest, as well as color contrast, in fabrics for apparel, upholstery, drapery, and other well-known uses.

The Jacobs et al. U.S. Pat. No. 3,113,413, discloses one form of slubbing apparatus by which one yarn strand is overfed with respect to another yarn strand. The two yarn strands pass through separate, spaced yarn guides mounted on a reciprocating slubber bar, and then are fed into an air jet in which slubs are formed in. the overfed yarn strand and attaching in some manner with the other yarn strand. The slubber bar is caused to reciprocate in a linear path at varying linear speed rates. At one moment a yarn strand may be passing through a yarn guide that has moved with the slubber bar so as to be farthest from the air jet while the other yarn strand moving through its yarn guide has been brought by the slubber bar to be closest to the air jet. As the farthest yarn strand moves back toward the air jet location an excess of yarn or the rate of yarn to the air jet from that strand is increased. The arrangement is such that first one yarn strand and then the other becomes in effect the overfed yarn strand. The mechanism controlling the movement and rate of travel of the slubber bar results in randomly spaced slubs. Jacobs et al., thus discloses mostly a mechanical form of slubbing. requiring a number of moving parts.

In the patent to Edwards et al., U.S. Pat. No. 3,174,271, another arrangement is disclosed by which slubs of random size and distribution along a continuous filament yarn is obtained. A single continuous filament yarn strand from a supply package is fed to a supply or feed jet, passing therethrough, and is forwarded by the feed jet in a high velocity stream of air to impinge against a screen at an angle of about 90, the air passing through the screen. A slub jet of the interlacing type forms a high velocity stream of air which is also directed perpendicularly against the screen at a location adjacent to the impingement of the air stream from the feed jet. The turbulence between the two streams causes the single yarn strand to twist, loop, and entangle on itself. The loops or fold of the entangled yarn mass are consolidated into slubs by withdrawing the single yarn strand through the slub or interlacing jet in a direction which is countercurrent to the jet stream from the interlacing jet. Further consolidation of the slubs is stated to be completed by a third jet located after the second jet to twist protruding loops or ends about the yarn. It is stated that a carrier yarn strand may be introduced at' either the first, second or third jet, but it is preferred to introduce the carrier yarn strand at (and within) the second or interlacing jet by feeding into the interlacing. jet through an opening in the side of the jet. As the slubbed yarn strand is pulled through the interlacing jet the slubs are consolidated in the yarn by intermingling of the folds and filaments of the slubs and the base or carrier yarn strand. Consolidation of the slubs in the yarn is completed by a third or torque jet to twist protruding loops or ends about the yarn. Edwards et al., thus discloses less of a mechanical form of slubbing than Jacobs et al., and depends on compressible fluids to achieve slubbing action.

The Hardy 111 patent, U.S. Pat. No. 3,296,785, an improvement over the arrangement shown in the Edwards et al. patent, discloses a somewhat similar arrangement as that disclosed in the Edwards et al. patent except that the screen has been completely enclosed at the sides and top to form a basket or box-like enclosure, and that a fourth jet or interlacing jet has been added preceding the torque jet. The boxlike enclosure guides the yarn strand through the turbulent zone during slub formation. The patentee states that the Edwards et al. patent discloses the desirability of using a torque jet to ply the slubyarn with an unslubbed carrier yarn to overcomeweak spots in the yarn within the slub regions. The patentee also states that while such plied yarns are useful in imparting a decorative effect to fabrics, the weaving performance during the conversion of yarn to fabric is not completely satisfactory when using modern, high-speed, mass-production operations. It is difficult to control the running tension under high speed conditions because of the continuously varying yarn diameter. The yarn is also more susceptible to damage in that the thicker slub portions may hang up when the yarn contacts various surfaces, causing the slub to strip back and result in yarn breakage. Maximum processability is obtained, therefore, when the slub yarn and the carrier yarn are plied together in such fashion that they function, as nearly as possible, as a unitary structure. Thus, Hardy lll patent discloses the addition of the fourth or interlacing jet, preceding the torque jet to obtain a more unitary structure. it is stated that it has been found necessary to use the interlacing jet in addition to, and in conjunction with, the torque jet; and that it was surprising that a significant degree of interlace between the slub yarn and the carrier yarn could be achieved while the'yarns are under the influence of a torque jet.

The Fujita et al. U.S. Pat. No. 3,591,955, discloses still another slubbing apparatus in which the conventional slubbing jet is replaced by a deflected flow arrangement of the supply jet. A supply jet nozzle extends into a domeshaped hood and is offset from the longitudinal axis of the hood on which the yarn withdrawal hole is located. A single yarn strand enters into the supply jet nozzle at the rear of the nozzle and is directed by a high velocity gas flowing through and out of the jet nozzle toward the dome-shaped apex of the hood. The gas flows along one side of the hood and is deflected rearwardly from the concave interior surface of the dome-shaped apex, and as the gas is being deflected rearwardly it serves to slub the yarn that is passing in a countercurrent direction. The yarn is dashed against the apex of the hood by the gas stream and the excess length of overfeed is then folded back on the subsequently continuing portion of the yarn by the deflection of the gas stream.

SUMMARY OF THE INVENTION mined percent into an enclosed, vented slubbing chamber, while the core yarn strand enters the slubbing chamber under predetermined tension. The core yarn strand enters the chamber at one end portion through one inlet and the slubbing yarn strand enters at the I same end portion into another inlet through a feed jet.

The feed jet introduces a stream flow of compressible fluid into the slubbing chamber, and a second jet at the opposite end of the chamber introduces into the chamber a stream flow of compressible fluid, the two stream flows being directed generally toward each other in opposition to the feed jet stream flow.

The opposing stream flows, preferably air, create swirling currents and turbulence in the enclosed, vented slubbing chamber. The resulting swirling currents and turbulence and adjusted by adjusting the jets so as to support the slubbing yarn strand generally free of the wall of the slubbing chamber, and to cause the overfed slubbing yarn strand to move freely about in the chamber relative to the core yarn strand. The slubbing yarn strand appears to flick back and forth and to swirl around along the length of the chamber relative to the length of the core yarn strand within the chamber. The individual filaments of the slubbing yarn strand, as a result of such free movement and being in such swirling currents and turbulence, appear to be caused to open and spread apart somewhat from the slubbing yarn strand, and at the same time form slubs at random intervals and in random lengths and random thicknessess apparently by the slubbingyarn folding randomly back and forth upon itself and by some twisting in one direction or the other. The opening and spreading apart of the individual filaments of the slub- I bing yarn strand results in the initiation of some entwining and interlacing or entanglement of the filaments with, around and along the length of the core yarn strand within the slubbing chamber, which entwining and interlacing or entanglement appear to become more complete and consolidated into a unitary bundle upon the two yarn strands exiting together from the chamber through the second jet and countercurrent to the stream flow of air into the chamber from the second I jet. the second jet preferably being a venturi or lofting breaks per yards of fabric, for instance, for one of the cellulose acetate slub yarns discussed later.

Since the supply yarn for the slubbing yarn strand and for the core yarn strand is preferably being withdrawn from separate yarn packages, it is also preferable that part way through the withdrawal process the slubbing yarn strand becomes the core yarn strand and the core yarn strand becomes the slubbing yarn strand so as to provide an even run-out of the yarn from the two yarn packages with minimum waste. Accordingly, the apparatus is arranged so that the inlet feed jet for the slub jet becomes only an inlet with the jet operation being preferably shut down while the other inlet through which the core yarn strand had been entering the slubbing chamber becomes an operating inlet feed jet. The yarn strand that was previously the core yarn strand becomes the slubbing yarn strand with feed rolls engaging and controlling the predetermined percent overfeed of the new slubbing yarn strand and disengaging from the yard that was previously the slubbing yarn strand so that itbecomes the new core yarn strand. it should be understood, however, that if the jet through which the core yarn strand enters the chamber remains in operation, the resulting product will have different characteristics. An advantage of the use of a positive feed arrangement such as the feed rolls is that it establishes a definite overfeed of the slubbing yarn strand.

The process and apparatus for practice of the process thus results in an improved random slub yarn, the yarn having improved weaving efficiency and resulting in a lower number of loom breaks, and wherein fewer operating components than that disclosed in some of the prior art are required to achieve a more unitized yarn bundle with the slubbing yarn strand being closely entwined and interlaced or entangled with the core yarn strand.

Although the slubbing chamber of this invention could be used to introduce only a single yarn strand, without introducing also a core yarn strand, the primary purpose of the invention is to obtain a more unitized bundle of yarn filaments comprising a supporting or core yarn strand and a slubbing yarn strand. The more unitized bundle is believed to occur in part as a result of introducing both strands in the slubbing chamber with the slubbing action taking place along the length of the core yarn strand as they both move through the slubbing chamber. ltis well-known that slubs tend to weaken yarn, thus the purpose of a core yarn strand is to strengthen slubbed yarn. Particularly in the instance of the use of cellulose acetate yarn it is not as strong as yarns such as polyester yarn,'and for weaving purposes it is usually considered to be more desirable to employ a supporting core yarn strand so as to minimize possible loom and quill breaks.

BRIEF DESCRlPTlON OF THE DRAWINGS In the drawings:

FIG. 1 is a front elevational view of the overall apparatus and illustrating the slubbing yarn strand moving freely about relative to the core yarn strand within the enclosed slubbing chamber;

HO. 2 is a side elevational view of the apparatus shown in FIG. 1;

FIG. 3 is an enlarged isometric view of the enclosed, vented slubbing chamber and of the jets leading into the chamber;

FIG. 3a is a view of the auxiliary yarn guide used at the inlet of the output jet; and

FIG. 4 is an'enlarged isometric view of another em bodiment of a slubbing chamber which is hingedso as to swing open to facilitate string-up of the two yarn strands and to provide an enclosed path for exhaust from the venting openings.

DESCRIPTION OF THE PREFERRED EMBODIMENT In reference tothe drawings, and initially to FIGS. 1 and 2, the yarn slubbing apparatus is designated generally at and constitutes one yarn position" of a possible plurality of yarnpositions. Two yarn ends or strands l2, 14 of essentially zero twist, continuous multifilament yarn, such as'of polyester, cellulose acetate or of other suitable manmade material and from suitable supply sources, such as separate yarn packages 12a, 14a, are guided over a movable yarn guide assembly 15, through a feed roll assembly 16 and into the em closed, vented slubbing chamber 18 through separate inlets 20, 22. Preferably, each of the inlets is a fluid jet, however, only one of the fluid jets operates as a jet for introducing therethrough into thechamber the yarn strand that constitutes the slubbing yarnstrand, while the other, preferably non-operating fluid jet merely serves in its quiescent state as an inlet into the chamber for the core yam strand.

The movable yarn guide assembly comprises an axially movable bar 15a on which yarn guide eyelets 15b are mounted. Upon axial movement of the bar in one direction or the other, as viewed from the front of the'apparatus shown in FIG. 1, the eyelets are shifted laterally either to-the right or to the left so as to guide either yarn strand 12 or yarn strand l4, whichever should be the slubbing yarn strand, into engagement between the input driven feed roll 24and pressure cot roll 26, and to guide the other yarn strand (the core yarn strand) from between the aforementioned rolls. In

this manner the slubbing yarn strand may be controlla-' bly and drivingly overfed at a predetermined percent, for instance such as percent overfeed, to the slubbing chamber. The arrangement thus provides for a definite. positive overfeed. The core yarn strand is introduced into the chamber under predetermined tension, passing through a suitable tension device (not shown) after leaving-the yarn package. The pressure cot roll 26 is preferably chamfered at its ends (not shown) to facilitate the'lateral movement of one yarn strand or the otherintodriven engagement between the input feed roll and pressurecot roll. After a predetermined period of operating with one set of packages,

preferably after'a doffing cycle, the movableyarn guide:

assembly is shifted-in the-opposite direction so that the core yarn strand becomes the slubbing yarn strand to be overfed at a predetermined percent, and the slubbingyarn strand becomes the core yarn strand that moves through the slubbing chamber under predetermined tension. In this manner substantially even runout of the packages is promoted, thereby reducing to a minimum any yarn material that may be remaining on one package when the other package has run out. Preferably, the supply packages contain enough yarn for two doffing cycles, but it shouldbe recognized that this aspect of the invention is a matter of choice. When the yarn guide assembly is shifted laterally, the operating input or feed jet is preferably shut down andthe quiescent jet is made operative. This shifting of the aforementioned components may be handled by operating personnel or may be accomplished automatically for all of the possible yarn positions in a line. j j

The slubbing yarn strand and the core yarn strand thus enter the slubbing chamberl8 at the same end of the chamber but through separate inlets. In FIG. 1 the input feed roll 24 and pressure'cot roll 26 are shown as being in driving engagement with yarn strand 12, therefore, yarn strand 12 is the slubbing yarn strand and yarn strand 14 is the core yarn strand.

The slubbing yarn strand 12 is pulled into the slubbing chamber by the action of the fluid jet constituting inlet 20, through which a stream flow of compressible fluid, such as air, flows into the chamber. An output jet 28 is positioned at the opposite end of the slubbing chamber and serves not only as an outlet for the two yarn strands but also provides a stream flow of compressible fluid, preferably air, into the chamber in countercurrent fluid flow to the inlet fluid jet stream" flow.

The resulting countercurrent fluid flow, as previously yarn strand. The slubbing yarn strand appears to flick back and forth and to swirl around along the length of the chamber relative, to the length of the core yarn strand which is being drawn under predetermined tension into the'chamber from the yarn package by the action of a winder located on the downstreamside of the slubbing chamber. As the excess amount of slubbing yarn strand is caused to move freely about the individual filaments of the strand appear to be caused to separate and-spread somewhat apart, so that not only are slubs of snarls and tangles formed at random intervals and in random lengths and random thicknesses in the slubbing yarn strand as apparently it folds randomly back and forth and twisting upon itself but the separated, spread fllaments also entwine somewhat, interlace or entangle somewhat around, with and along the core yarn strand so as to lock such back and forthfoldings and twistings to the length of the core'yarn strand within the slubbing chamber. The two yarn strands, as formed into a single yarn bundle within the slubbing chamber 18, become more completely entwined and interlaced or entangled and are firmly consolidated into a unitized bundle by exiting together through the output jet 28'against' the countercurrent flow of fluid feeding into thechamber from theoutput jet. Preferably, the jets are adjusted to provide a greater flow into the chamber through the second or output jet. The resulting yarn product then passes under and over a pair of tension guides 30, 32, under guide 34 and is wound up on a package, such as by a surface driven winder 36.

The slubbing chamber 18 is, as previously stated, enclosed, and is vented by a series of slots 38 preferably located at each end of the chamber and extending in a direction preferably that is non-parallel to the axial 7 length of the chamber. In this manner the air being introduced into the chamber by the opposed jets is vented from the chamber in a controlled manner, with generally no impinging of the slubbing yarn, whichis not under tension, against the interior wall of the chamber. The interior of the chamber is preferably cylindrical. The width and position of the slots is preferably such that the slubbing yarn filaments will not catch or become entrapped by or drawn through the slots;

.hence the slots are stated to extend in a non-parallel ditermed the venting area." For one of the slubbing chambers to be discussed herein, the vented or venting area is about 1.43 square inches. It is found that as the venting area is increased the slub length, slub ratio and slub spacing also increaserThus', the venting area constitutes one of the control factors that may be varied to achieve different effects in fabrics made from the random slub yarn, the resulting end product of this inventlon. Another control factor that may be varied to achieve different yarn effects is the chamber size, such as the change in the length or the diameter, or changing dimensions in both. For instance, with respect to one of the yarns to be described, .the slubbing chamber mentioned that has a vented area of I43 square inches also has an inside diameter of 2 inches and a length of 12 inches. These dimensions may be varied to achieve certain desired yarn effects assuming other factors such as air jet pressures, venting area and amount of overfeed remain the same. For instance, it is possible to have a series of different sizes of chambers fabricated for ready insertion inthe slubbing apparatus when certain types of random slubbing yarns are desired. It generally does not appear practical, although possible, to use jet pressures as'control variables, however, because of the possibility of some adverse effect on yarn quality as jet pressures are increased. This depends, of course, upon the type of material employed for the yarn strands. Higher air pressures are possible and even more feasible withpolyester yarn, which is a tougher yarn, than for cellulose acetate yarn. Lower jet pressures, where possible, are more advantageous, however, and are more economical because of the reduced air consumption.

Although the opposing jets, input or feed and output jets, may be positioned so that their air stream flows are directly opposed to each other, it is found that for certain desirable novelty slub effects in fabrics it is preferable to have a "jet offset," which is defined as the distance between centerlines projected from the axes of the inlet or feed jet and the output jet. The amount of jetoffset varies, depending upon the diameter of the chamber and upon the product to be produced. As the jet offset or offset distance increases, assuming other factors previously mentioned remain the same, the slub length, slub ratio and spacing betweenslubs increases. Directly opposed air flows, or zero distance jet offset, is found to result in a more disturbed type of air flow and produces a slub that is shorter in length and smaller in diameter with smaller spacings between the slubs. The distance for the offset employed with the slubbing chamber mentioned above that has a 2 inch inside diameter and a 12 inch length is five-eighths inch-and results in the production of one of the slubbed yarn products to be discussed later. If either jet is positionedtoo close to the slubbing chamber wall the slubbing yarn strand may be blown against the wall, changing the effect of its entanglement with the core yarn strand and interfering with the formation of the slubs desired. it will thus be apparent that jet offset is another 'variable control factor.

The percent overfeed of the slubbing yarn is still another variable control factor in the practice of the invention. It has been found, for instance, that approximately an overfeed greater than 5 percent is required before any significant slubbing can be distinguished.

This assumes, of course, that other condtions favorable to the formation of slubs are present. At l0 percent overfeed, the slubs appear to be quite short. For instance, in'experimenting with cellulose acetate yarns it was noted that under certain operating conditions the slub lengths were approximately an inchor slightly less in length. On the other hand, when 100 percent overfeed was used, the slubs under still different operating conditions were quite long. Naturally, other operative conditions previously described or to be described herein can be varied as well so that in some instances at lOO percent overfeed the slubs maybe short. As will be seen in one of the tables disclosed herein in which cellulose acetate .yarn was run some slubs were about 2.5 inches in length while another yarn and under some different conditions at the same I00 percent overfeed the slubs were better than 18 inches in length. The slubs were also found to be not only longer but also larger in cross-section. It is preferable in practice and for the present current style demandsto operate the percent overfeed in the range of approximately about 10 percent to about 30 percent, and preferably at about 20 percenL'This appears to result in the least'amount of operating and processing difficulties as well as the least processing difficulties in weaving. Thus, percent overfeed is another variable control factor.

When alternating the overfeed by means of the movable yam guide assembly 15 and changing of the input feed jets, it is essential to assure that the slubbing yarn strand feed path into and through the output jet from the chamber be the same in order to assure that there is no change in yarn appearance or quality differences. It has been found that this same path may be accomplished by providing an auxiliary yarn guide within the slubbing chamber at the inlet of the output jet. in reference to H68. 3 and 3a, the auxiliary yarn guide is shown at 40. The design of the auxiliary yarn guide is found to be fairly critical. A small tube 42 is used for the centering guide because the use of eyelets was found to cause breakdowns due to filaments wrapping around the eyelets. The length of the tube used prevents such wrapping. it was also found that excessive bulk in the supporting structure for the tube blocked the air flow from the jet and was detrimental to the operation of the chamber. Therefore, the illustrated supporting structure 44 for the tube 42 was made just large enough to insure that the tube is not easily bent out of alignment and does not interfere with air flow from any of the jets. The small diameter tube provides precise alignment for the yarn, and also appears to serve as a quality control device. It is observed that if the slubs in the yarn have been formed poorly, they will not pass through the small opening in the tube and are stripped back by the tube. Accordingly, the yarn position that would be represented by one such slubbing apparatus 10 will not run" if.it is not adjusted properly so that the slubs will pass through the small tubular opening in the auxiliary yarn guide on the output jet. It should be recognized, of course, that a jet could be made having an integrally formed guide, if desired.

The fluid jets that may be used in practice of this invention may be of character such as disclosed in the Dyer patent, U.S. Pat. No. 2,924,868. Both the input and output jets may be of a venturi type or what may be known in the ari as lofting jets," even though technically speaking they are not being used as lofting jets. The invention, however, should be understood as not being restricted to a lofting or venturi-type jet. The purposes of the input jet are to have sufficient pulling power to pull the slubbing yarn strand into the slubbing chamber, and to blow a compressible fluid, such as air, into the chamber to create with the fluid flow from the output jet turbulence and swirling air currents. Thus any jet that has these two characteristics should serve as well for the input jet. The output jet must have larger fluid passages than the input jet for the resulting slubs to pass therethrough in exit from the chamber. The output jet must also exhaust most of its compressible fluid or air into the chamber, and must be of a character to cause entangling or interlacing. Although the jet used at the output position in the practice of this invention happens to be of a lofting type such as indicated above, it is not being used as such since the yarn in exiting from the chamber through the jet is in a sense running backward through the jet.

The input jet is preferably adjusted for cellulose acetate yarn so that 1.5 inches of mercury vacuum is obtained at the jet inlet at a supply air pressure of about 3 to 5 p.s.i.g. The outputjet, for cellulose acetate yarn, is adjusted to about to p.s.i.g. These pressures, of course, will differ depending upon the size or design or type of jets used.

The air provided to the fluid jet is preferably heated to a temperature of l00-l F. when acetate yarn, for example, comprises the core and slubbing yarn strands. The heated air appears to facilitate yarn entanglement and to minimize any broken filaments.

Since such heated air would impose an additional load on an air conditioning system employed in the yarn production room to control yarn quality, and would make it uncomfortable for operating personnel in the near vicinity, FIG. 4 discloses a modification of the slubbing chamber shown in FIG. 3 wherein the vented areas of the slubbing chamber are completely enclosed so that the heated air can be exhausted from the chamber without entry into the ambient air about the apparatus in general. The modification, indicated generally at 46, is essentially square in cross-section on the outside while retaining a circular cross-section interior slubbing chamber 18'. It is thought that the circular interior cross-section provides the best slubforming action. The slubbing chamber is hinged to open along its longitudinal axis. The square-like exterior of the chamber provides flat mounting surfaces for the hinges (not shown) and latch 48 while allowing sufficient material through which tapped holes for such hinges and latch may be made. Passages are provided between the inner and outer surfaces of the slubbing device to define a closed path for collection of exhaust air. The vented area, for a chamber having a 2 inch inside diameter and being 12 inches in length, appears to be about 1.36 square inches, as corrected for the holes and passages through which the air has to flow in the hinged, enclosed embodiment. The other components which are similar to those components described in the embodiment shown in FIGS. 1 through 30 are identified with like but primed reference numbers.

One of the advantages in the use of the hinged slubbing chamber is that it is easier for the operator to thread-up. Another advantage is that the noise level is significantly reduced in the operating area due to the enclosure of the vented areas of the slubbing chamber. Still another advantage is that heated air, and any lubricant in the air that may be from the yarn, are exhausted through a collector system that is suitably connected to the enclosed slubbing chamber such as by the exhaust connection shown at in FIG. 4. This provides a more healthful atmosphere in which operators may work. and the air'conditioning in the rooms in which the operating equipment is located is not impaired by such heated jet air. It is also easier to clean any waste yarn from the chamber in the event of any breakdown. Also, the jets may be mounted in a fixed mounting without having to be removed for threading-up.

In operation of the slubbing apparatus, it has been found that for best results adjustment of the input and output jets should be made so that the gathering point for the two yarn strands in the slubbing chamber, i.e., where the slubbing yarn strand appears to initially come together with the core yarn strand, should occur at about one-quarter of the chamber length from the input jet end. In order to observe the gathering point location, it is preferable that the slubbing chamber be made of transparent material such as a suitable plastic. When vacuum is employed on the exhaust system or the collector system, it is noted that changing the vacuum has a similar effect as changing the venting area. For instance, controlled vacuums ranging from 0 to 7 inches of water were experimentally applied to the collector systems connected to the completely enclosed slubbing chamber. It was noted that at one inch of water the yarn gathering point moved farther from the input end. It thus appears to be preferable to hold such vacuum, when applied, within a range of 0-] inch of water or less. Therefore, it may be seen that vacuum may also be used as a variable control factor.

TABLE A shows twelve different yarn samples of cellulose acetate yarn that were run under varying conditions, such as by the change in size of the slubbing chamber; the change in venting area; the change in jet offset; and the percent overfeed of theslubbing yarn strand. In each instance the operating speed of the winder was about 500 yards per minute. It should be recognized, however, that the operating speed may be increased or decreased, as desired. Also, for each yarn sample, the input feed jet pressure was about 3 p.s.i.g. and the output feed jet pressure was about 15 p.s.i.g. In each instance, also, the core yarn strand was under a tension of about 3 grams.

TABLE A also shows that the yarn samples were analyzed for slub size and distribution. An Uster Evenness Tester (a commercially available instrument) was used which is an instrument designed for determining the del l gree of denier variation in yarns. About I yards for each of the twelve yarn samples were analyzed, and the results were extrapolated to obtain values for 1,000 yards of sample. As a check upon the accuracy of the 12 TABLE B 220 Denier Random Slub Yarn Test Data v St 1 E 1 E 1 1 E 1 2 E r 1 3 Uster recordings regarding the maximum denier ratios, 5 am y e e xamp e xamp e e a series of individual slub samples were measured for Slub Chamber Size. 2x12 2%X24 2%)(18 denier ratio both by the Uster instrument and by the 33:2? x Length manual operation of weighing the slubs on laboratory Supply Yarn 100/25/0 100/2510 100/25/0 BRT.

BRT. BRT. balances. For the weighing test, the sample slubs were Theoretical Denier 220 220 220 cut mm 0.25 inch long segments. These segments were then weighed individually so as to ascertain the maxii'z f pgg mum denier ratio within each slub. 133%,;

TABLE B, entitled 220 Denier Random Slub Yarn Actual denier 215.5 2l8.5 214.1

10 Tenacity. G/D Test Data, shows three further examples of cellulose Between Slubs mg no Lug acetate yarn, each yarn being run in one of three differ- With slubs 0.91 1.02 0.92

Elongation. '/r ent sized slubbmg chambers at a wind up yarnspeed of Between Slubs 2 I 4 24.6 2 I 1 about 300 yards per minute. The diameter dimension slabs 183 18,7 shown for each of the slubbmg chambers of the cylint g Effichicncy 84 I 36 31 n t o r drical exter or type shown in HQ. 3 is the inside diamef f f g xfg 0006 0 (m2 ter of the chamber. Each slubbmg chamber was made Approximate r011 94 100 78 1 n n I from a suitable clear plast c in order to better observe whether the slubbing action was performing properly. pcrrmmancc The l0O/25/0 BRTr" means that the supply yarn for Yards, 257 252 Cupping breaks per 0.8 I O 0 each of the slubbmg yarn strands and the core yarn 100 yards 1 strands was I00 denier, 25 filaments in a yarn strand; 25 x35 breaks p I -0 the 0 stands for zero twist, and BRT stands for b bright yarn or yarn having no delusterant in the cellulose acetate dope. The tension for the core yarn strand in the different yarn styles varied from about 2 /2 grams TABLE C to about 3% grams for the six yarn positions that were Characteristics of Random Slub Yarn Style Example I from Table B Yarn style Example 1 iii TABLE B was found to reof slubs per L000 yards v L296 sult in satisfactory machine efficiency, weaving per- Average slub length 2.1 inches formance and fabric appearance. Yarn style Example z isg s zig ga mchcs length i 3 had a successful weaving performance. but its proa ofslubshavingadenier ratio greater than 1.1 and 56% cessing efficiency on the slubbing apparatus was rather less low. The acceptable level for the weaving performance of acetate slub yarns was set at four weaving breaks or f h d loops randomly spaced along the resulting less per 100 yards of fabric t a ea ng Speed Of slub yarn product between the slubs. In some instances 190-200 picks per minute. The best weaving perform- 40 only the slubbing yarn strand has formed into an arched ance for yarn style Example 2 at 500 yar per minute loop, and in other instances both the slubbing yarn processing speed was about 8 breaks Pe 100 y strand and the core yarn strand have together formed When the speed was lowered to a out 300 y r p r into an arched loop. The arched loops .did not interfere minute the performance improved to 5.2 breaks per with weaving efficiency, l00 yards. Since yarn .style Example l appeared to In employing the slubbing apparatus for polyester present a better all around product only it was analyzed yarns it was observed that significantly higher jet presfor slub pattern with the aid of the Uster Evenness Tessures must be used, such as about p.s.i.g. or greater ter. The values obtained are shown on TABLE 7 at the output jet as compared to about 10 to l5 p.s.i.g. Another characteristic observed in slub yarn repreemployed for cellulose acetate yarn. The pressures emsented by yarn style Example 1 in TABLE B, for in- 50 ployed for the input feed jet, however, appeared to be stance, but not specifically, measured, is the formation satisfactory, requiring the same settings and air pres- TABLE A Sample No. Slub Chamber Vent Area in .let Offset in Percent No Slubs per Average Slub Average Slub Denier Size Diameter X square inches inches Overfeed 1000 Yards Length (inches) Ratio Length (inches) 1 1%x3 0.78 7/l6 10 230 0.9 2.1 2 mxs 0.78 7/1 6 30 1125 1.5 2.4 3 1%X3 0.78 7/16 3182 2.5 3.0 4 2506 1.25 l 1/4 10 357 1.0 2.1 5 2596 1.25 1 1/4 30 i601 1.4 2.5 6 29100 1.25 1 1/4 100 2760 2.3 3.8 7 114x24 0.78 7/l6 i0 368 0.9 2.3 s 1%x24 0.78 7/16 30 979 3.0 4.0 9 1%x24 0.78 7/16 100 i206 5.7 5.8 10 255x24 1.25 1 1/4 10 240 2.2 3.1 11 2%x24 1.25 1 1/4 30 500 5.8 4.5 12 205x24 1.25 1 1/4 100 v 18.7 6.8

sures as for cellulose acetate yarn. It is thought that modifications can be made in the output jet to enable the process to be more efficient. The resulting fabric woven from such polyester yarn contained some objectionable filament loops on the face of the fabric, but in experimenting with modifications to the output jet the number of these loops was reduced but not eliminated. It is thought, however, that further work along the line of modifying the output jet can result in improved fabric appearance and weaving efficiencies by practice of the invention disclosed herein.

Other experiments were also made in practicing the invention by employing a polyester core yarn strand and a cellulose acetate slubbing yarn strand. No difficulties were encountered in processing the yarn and weaving it.

It is thought that the relatively few examples of yarn characteristics that have been discussed in more detail will serve to show the effectiveness of the invention and the possibilities inherent in its practice. I merely mention other yarns which I have tried to show that they may be used as well, making whatever adjustments necessary of the components making up the apparatus for processing such other yarns and for obtaining whatever fabric effects that may be desired. Since it is difficult, if not impossible, to freely describe the characteristics of the yarn products that may be obtained in the practice of my invention, I also consider the yarn product from the practice of the method to be part of my invention.

While the invention has been described in detail with particular references to preferred embodiments thereof, it will be understood that variations and modifications can be effected within the spirit and scope of the invention as described hereinabove and as defined in the appended claims.

I claim: 1. An apparatus adapted to form in a yarn slubs of random length and random diameter at random spaced intervals along the yarn, and comprising:

an enclosed slubbing chamber defining at one end portion a first inlet opening through which a slubbing yarn strand may be introduced into the chamber and a second inlet opening through which a core yarn strand may be introduced into the chamber under tension for movement through the chamber along with the slubbing yarn strand, and defining at the opposite end portion an outlet opening through which the slubbing yarn strand and core yarn strand exit together from the chamber;

means for introducing the slubbing yarn strand into the first inlet opening at a predetermined percent of overfeed;

means for continuously introducing into the slubbing chamber at one end portion thereof a first stream flow of compressible fluid and at the opposite end portion thereof a second stream flow of compressible fluid, the two stream flows being directed toward each other to create swirling turbulent stream flows of said compressible fluid, and adjusting such stream flows a. to support the slubbing yarn strand generally free from contact with the chamber wall, and

b. to move the slubbing yarn strand freely about in the chamber relative to the core yarn strand, the slubbing yarn strand forming slubs and entwining and entangling with the core yarn strand;

said slubbing chamber further defining venting openings adjacent the end portions of the slubbing chamber and through which venting openings the compressible fluid is exhausted in a controlled manner from the chamber; and

means for'moving the slubbing yarn strand and core yarn strand through and from the slubbing chamber and countercurrent to the second stream flow as the yarn strands move out of the chamber.

2. An apparatus as defined in claim 1, and wherein said means for continuouslyintroducing said stream flows of compressible fluid includes:

a first jet means positioned within the first inlet opening of the slubbing chamber and adapted to introduce into the chamber one of the stream flows of compressible fluid and to receive therethrough and feed into the chamber along with the compressible fluid the slubbing yarn strand; and

a second jet means positioned within the outlet opening of the slubbing chamber and adapted to introduce into the chamber another of the stream flows of compressible fluid and to receive therethrough countercurrent to the stream flow from the second jet means the yarn strands as they exit from the chamber.

3. An apparatus as defined in claim 2, and wherein the axis of the first jet means is offseta predetermined distance from the axis of the second jet means.

4. An apparatus as defined in claim 2, and wherein the second jet means has a greater stream flow than the stream flow of the first jet means.

5. Anapparatus as defined in claim 2, and wherein said first jet means has a stream flow of compressible fluid of about 3 to 5 p.s.i.g. and the second jet means has a stream flow of compressible fluid of about 10 to 15 p.s.i.g.

6. An apparatus as defined in claim 2, and further comprising an auxiliary yarn guide within the slubbing chamber, and positioned in centered relation at the inlet of the second jet means, the auxiliary yarn guide having a small diameter tube adapted to receive and guide therethrough the yarn strands, and a support means for the tube to hold the tube in said centered relation.

.7. An apparatus as defined in claim 1, and wherein the'interior of the slubbing chamber is cylindrical in configuration.

8. An apparatus as defined in claim 1, and wherein said venting openings are defined in the interior wall of the slubbing chamber as slits of predetermined width and length and extend in a direction non-parallel with respect to the longitudinal axis of the chamber.

9. An apparatus as defined in claim 1 and further comprising means for enclosing the venting openings and providing a closed path outlet for the compressible fluid as it is exhausted from the chamber through the venting openings.

10. An apparatus as defined in claim 1, and wherein said means for introducing the slubbing yarn strand into the first inlet opening includes a driving roll arrangement for drivingly engaging the slubbing yarn strand, and the apparatus further comprising a movable yarn guide means for shifting the slubbing yarn strand out of driving engagement with the driving roll arrangement and for shifting the core yarn strand into driving engagement with the driving roll arrangement, thereby changing the slubbing yarn strand to a core yarn strand and the core yarn strand into a slubbing yarn strand; and a third jet means positioned within the second inlet means and adapted when inoperative to serve as an inlet for a core yarn strand and when operative to serve as an inlet for aslubbing yarn strand.

11. An apparatus as defined in claim 1, and wherein the predetermined percent of overfeed is in the range of about percent to 30 percent.

12. The method of forming in a yarn slubs of random length and random diameter at random spaced intervals along the yarn, said method comprising:

introducing into the enclosed chamber at one end portion thereof a first stream flow of compressible fluid and introducing into the enclosed chamber at the opposite end portion thereof a second stream flow of compressible fluid, and directing the two streams flows toward each other and thereby forming swirling turbulent stream flows of compressible fluid;

introducing into the chamber at said one end portion a slubbing yarn strand at a predetermined percent of overfeed and a core yarn strand under predetermined tension, the slubbing yarn strand being introduced through and along with the first stream flow;

adjusting the first and second stream flows at to support the slubbing yarn strand generally free from contact with the chamber wall, and

be to move the slubbing yarn strand freely about in the chamber relative to the core yarn strand, the

slubbing yarn strand forming slubs and entwining and entangling with the core yarn strand;

exhausting from the enclosed chamber the stream flows of compressible fluid in a controlled manner;

and removing the slubbing yarn strand and thecore yarn strand from the enclosed chamber at said opposite end portion through and countercurrent to the second stream How of compressible fluid.

13. The method as defined in claim 12, and comprising introducing at said opposite end portion a greater stream flow of compressible fluid than the first stream flow of compressible fluid.

14. The method as defined in claim 12, and wherein said first stream flow is introduced into the enclosed chamber at about 3 to 5 p.s.i.g. and said second stream flow is introduced into the enclosed chamber at about 10 to 15 p.s.i.g.

15. The method as defined in claim 12, and wherein said first and second stream flows of compressible fluid are introduced into the enclosed chamber directly opposed to each other.

16. The method as defined in claim 12, and wherein said first and second stream flows of compressible fluid are introduced into the enclosed chamber offset with respect to each other.

17. The method as defined in claim 12, and further adjusting the amount of the first and second stream flows until the slubbing yarn strand gathers with the core yarn strand at about one-quarter of the length of the enclosed chamber from the end portion at which the slubbing yarn strand and core yarn strand are introduced into the chamber.

18. A yarn slub product comprising a slubbing yarn strand and a core yarn strand, the product made in accordance with the method defined in claim 12. 

1. An apparatus adapted to form in a yarn slubs of random length and random diameter at random spaced intervals along the yarn, and comprising: an enclosed slubbing chamber defining at one end portion a first inlet opening through which a slubbing yarn strand may be introduced into the chamber and a second inlet opening through which a core yarn strand may be introduced into the chamber under tension for movement through the chamber along with the slubbing yarn strand, and defining at the opposite end portion an outlet opening through which the slubbing yarn strand and core yarn strand exit together from the chamber; means for introducing the slubbing yarn strand into the first inlet opening at a predetermined percent of overfeed; means for continuously introducing into the slubbing chamber at one end portion thereof a first stream flow of compressible fluid and at the opposite end portion thereof a second stream flow of compressible fluid, the two stream flows being directed toward each other to create swirling turbulent stream flows of said compressible fluid, and adjusting such stream flows a. to support the slubbing yarn strand generally free from contact with the chamber wall, and b. to move the slubbing yarn strand freely about in the chamber relative to the core yarn strand, the slubbing yarn strand forming slubs and entwining and entangling with the core yarn strand; said slubbing chamber further defining venting openings adjacent the end portions of the slubbing chamber and through which venting openings the compressible fluid is exhausted in a controlled manner from the chamber; and means for moving the slubbing yarn strand and core yarn strand through and from the slubbing chamber and countercurrent to the second stream flow as the yarn strands move out of the chamber.
 2. An apparatus as defined in claim 1, and wherein said means for continuously introducing said stream flows of compressible fluid includes: a first jet means positioned within the first inlet opening of the slubbing chamber and adapted to introduce into the chamber one of the stream flows of compressible fluid and to receive therethrough and feed into the chamber along with the compressible fluid the slubbing yarn strand; and a second jet means positioned within the outlet opening of the slubbing chamber and adapted to introduce into the chamber another of the stream flows of compressible fluid and to receive therethrough countercurrent to the stream flow from the second jet means the yarn strands as they exit from the chamber.
 3. An apparatus as defined in claim 2, and wherein the axis of the first jet means is offset a predetermined distance from the axis of the second jet means.
 4. An apparatus as defined in claim 2, and wherein the second jet means has a greater stReam flow than the stream flow of the first jet means.
 5. An apparatus as defined in claim 2, and wherein said first jet means has a stream flow of compressible fluid of about 3 to 5 p.s.i.g. and the second jet means has a stream flow of compressible fluid of about 10 to 15 p.s.i.g.
 6. An apparatus as defined in claim 2, and further comprising an auxiliary yarn guide within the slubbing chamber, and positioned in centered relation at the inlet of the second jet means, the auxiliary yarn guide having a small diameter tube adapted to receive and guide therethrough the yarn strands, and a support means for the tube to hold the tube in said centered relation.
 7. An apparatus as defined in claim 1, and wherein the interior of the slubbing chamber is cylindrical in configuration.
 8. An apparatus as defined in claim 1, and wherein said venting openings are defined in the interior wall of the slubbing chamber as slits of predetermined width and length and extend in a direction non-parallel with respect to the longitudinal axis of the chamber.
 9. An apparatus as defined in claim 1 and further comprising means for enclosing the venting openings and providing a closed path outlet for the compressible fluid as it is exhausted from the chamber through the venting openings.
 10. An apparatus as defined in claim 1, and wherein said means for introducing the slubbing yarn strand into the first inlet opening includes a driving roll arrangement for drivingly engaging the slubbing yarn strand, and the apparatus further comprising a movable yarn guide means for shifting the slubbing yarn strand out of driving engagement with the driving roll arrangement and for shifting the core yarn strand into driving engagement with the driving roll arrangement, thereby changing the slubbing yarn strand to a core yarn strand and the core yarn strand into a slubbing yarn strand; and a third jet means positioned within the second inlet means and adapted when inoperative to serve as an inlet for a core yarn strand and when operative to serve as an inlet for a slubbing yarn strand.
 11. An apparatus as defined in claim 1, and wherein the predetermined percent of overfeed is in the range of about 10 percent to 30 percent.
 12. The method of forming in a yarn slubs of random length and random diameter at random spaced intervals along the yarn, said method comprising: introducing into the enclosed chamber at one end portion thereof a first stream flow of compressible fluid and introducing into the enclosed chamber at the opposite end portion thereof a second stream flow of compressible fluid, and directing the two streams flows toward each other and thereby forming swirling turbulent stream flows of compressible fluid; introducing into the chamber at said one end portion a slubbing yarn strand at a predetermined percent of overfeed and a core yarn strand under predetermined tension, the slubbing yarn strand being introduced through and along with the first stream flow; adjusting the first and second stream flows a. to support the slubbing yarn strand generally free from contact with the chamber wall, and b. to move the slubbing yarn strand freely about in the chamber relative to the core yarn strand, the slubbing yarn strand forming slubs and entwining and entangling with the core yarn strand; exhausting from the enclosed chamber the stream flows of compressible fluid in a controlled manner; and removing the slubbing yarn strand and the core yarn strand from the enclosed chamber at said opposite end portion through and countercurrent to the second stream flow of compressible fluid.
 13. The method as defined in claim 12, and comprising introducing at said opposite end portion a greater stream flow of compressible fluid than the first stream flow of compressible fluid.
 14. The method as defined in claim 12, and wherein said first stream flow is introduced into the enclosed chamber at about 3 to 5 p.s.i.g. and said sEcond stream flow is introduced into the enclosed chamber at about 10 to 15 p.s.i.g.
 15. The method as defined in claim 12, and wherein said first and second stream flows of compressible fluid are introduced into the enclosed chamber directly opposed to each other.
 16. The method as defined in claim 12, and wherein said first and second stream flows of compressible fluid are introduced into the enclosed chamber offset with respect to each other.
 17. The method as defined in claim 12, and further adjusting the amount of the first and second stream flows until the slubbing yarn strand gathers with the core yarn strand at about one-quarter of the length of the enclosed chamber from the end portion at which the slubbing yarn strand and core yarn strand are introduced into the chamber.
 18. A yarn slub product comprising a slubbing yarn strand and a core yarn strand, the product made in accordance with the method defined in claim
 12. 